Update2:
Thank you @abit. All the below code change compiled without error.

FC_CAPTURE_AND_LOG( (_user_agent_string) )

• add a line friend bool operator<(const address& a, const address& b); >to class address
• add an implementation to ip.cpp?
  bool operator<( const address& a, const address& b ) { return uint32_t(a) < uint32_t(b); }

Except the latest commit. It has 7 error:
4 reference to raw.hpp line 294:
c2668: fc::raw::unpack : ambiguous call to overload function
and 3 reference to variant.hpp line53:
c2668 fc::from_variant : abmiguous call to overload funciotn

I don't think it is related to the code change.